Thrombolytic efficacy and safety of recombinant scu-PA in a rabbit retinal vein occlusion model

Retinal vein occlusion (RVO) has become the second most common retinal vascular disease after diabetic retinopathy. Existing therapeutic approaches, including intravitreal injection of antivascular endothelial growth factors (anti-VEGFs) and/or glucocorticoids and laser therapy, primarily address secondary macular edema and neovascularisation. However, these strategies do not address the underlying cause of the disease and may have harmful side effects. There is an urgent need for therapies that have a better prognosis and include the administration of thrombolytics at an early stage. Therefore, in the present study, we investigated the thrombolytic effect of treatment with recombinant human Single-chain urokinase-type plasminogen activators (scu-PA)and the differences in its efficacy at different doses in a rabbit RVO model. In addition, through a series of ophthalmological examinations, such as optical coherence tomography (OCT) and electrophysiology, conducted to ascertain the effects of treatment with scu-PA on the ocular fibrinolytic system, we noted a definitive safety window for the vitreous administration of scu-PA. Therefore, this study is the first to confirm that an intravenous or vitreous cavity injection of scu-PA has definitive potential for treating RVO; however, additional clinical studies are needed for further validation.